From f2c64ef519b38a4328809b27b4a3a8e0c26e9709 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Thu, 16 Aug 2012 23:11:47 +0000
Subject: Add an MCID::Select flag and TII hooks for optimizing selects.

Select instructions pick one of two virtual registers based on a
condition, like x86 cmov. On targets like ARM that support predication,
selects can sometimes be eliminated by predicating the instruction
defining one of the operands.

Teach PeepholeOptimizer to recognize select instructions, and ask the
target to optimize them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162059 91177308-0d34-0410-b5e6-96231b3b80d8
---
 utils/TableGen/CodeGenInstruction.cpp | 1 +
 utils/TableGen/CodeGenInstruction.h   | 1 +
 utils/TableGen/InstrInfoEmitter.cpp   | 1 +
 3 files changed, 3 insertions(+)

(limited to 'utils')

diff --git a/utils/TableGen/CodeGenInstruction.cpp b/utils/TableGen/CodeGenInstruction.cpp
index 33381e9..12e153a 100644
--- a/utils/TableGen/CodeGenInstruction.cpp
+++ b/utils/TableGen/CodeGenInstruction.cpp
@@ -297,6 +297,7 @@ CodeGenInstruction::CodeGenInstruction(Record *R) : TheDef(R), Operands(R) {
   isCompare    = R->getValueAsBit("isCompare");
   isMoveImm    = R->getValueAsBit("isMoveImm");
   isBitcast    = R->getValueAsBit("isBitcast");
+  isSelect     = R->getValueAsBit("isSelect");
   isBarrier    = R->getValueAsBit("isBarrier");
   isCall       = R->getValueAsBit("isCall");
   canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
diff --git a/utils/TableGen/CodeGenInstruction.h b/utils/TableGen/CodeGenInstruction.h
index 3ba9f24..95b572d 100644
--- a/utils/TableGen/CodeGenInstruction.h
+++ b/utils/TableGen/CodeGenInstruction.h
@@ -222,6 +222,7 @@ namespace llvm {
     bool isCompare;
     bool isMoveImm;
     bool isBitcast;
+    bool isSelect;
     bool isBarrier;
     bool isCall;
     bool canFoldAsLoad;
diff --git a/utils/TableGen/InstrInfoEmitter.cpp b/utils/TableGen/InstrInfoEmitter.cpp
index 3adb869..b41ad94 100644
--- a/utils/TableGen/InstrInfoEmitter.cpp
+++ b/utils/TableGen/InstrInfoEmitter.cpp
@@ -319,6 +319,7 @@ void InstrInfoEmitter::emitRecord(const CodeGenInstruction &Inst, unsigned Num,
   if (Inst.isCompare)          OS << "|(1<<MCID::Compare)";
   if (Inst.isMoveImm)          OS << "|(1<<MCID::MoveImm)";
   if (Inst.isBitcast)          OS << "|(1<<MCID::Bitcast)";
+  if (Inst.isSelect)           OS << "|(1<<MCID::Select)";
   if (Inst.isBarrier)          OS << "|(1<<MCID::Barrier)";
   if (Inst.hasDelaySlot)       OS << "|(1<<MCID::DelaySlot)";
   if (Inst.isCall)             OS << "|(1<<MCID::Call)";
-- 
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